1. Field of the Invention
The invention relates to a reversing element for seat belt systems in motor vehicles.
2. The Prior Art
A reversing element known from DE 100 11 725 C1 is designed as a stamped steel sheet part designed so that the reversing element can be mounted within the encasement of a B-post of a motor vehicle. A multi-stage reshaping process is required for producing this reversing element. The adaptation of the reversing element to different installation situations results in a high cost manufacturing and engineering.
The invention relates to a reversing element or seat belt guide that can be adapted to different installation situations with simple means. With a covered or semi-covered installation within the post of a motor vehicle, the opening required for the passage of the seat belt within the covering (or lining) has to be closed by a sight shutter or cover on the vehicle side which permits pivotal movements of the reversing element.
One object of the invention is to provide a set of structural components for reversing elements of seat belt systems in motor vehicles. This set is comprised of at least the following components:
A metal body produced from a steel sheet by cold forming. This body comprises a fastening opening in a mounting surface on the backside; a belt eye, and a belt-guiding segment framing the belt eye on the underside and on the sides. This segment for guiding the belt forms a running surface with a rounded cross section for a seat belt, and a double-walled edge profile for the connection of plastic profiles.
There is also at least one plastic adapter comprising a collar that can be inserted in the fastening opening of the metal body, and a displacing body that can be fixed on the upper edge of the belt eye for limiting the width of the gap of the belt slot.
There is also a set of profiled elements comprising differently shaped plastic profiles that can be laterally pushed onto the edge profile of the metal body and coupled in pairs by a plug connection.
The metal body, as a standard structural component, has uniformly fixed dimensions irrespective of the concrete installation situation of the reversing element. This reversing element permits the installation of the metal body in the B-post of motor vehicles. Furthermore, the set of profiled elements comprises plastic profiles designed as sight shutters whose form is adapted to the concrete installation situation in a motor vehicle. If the reversing element is installed in a covered or half-covered manner, these plastic profiles engage from the edge of an opening from behind, receiving the reversing element which permits pivotal movements in a covering on the side of the body of the vehicle.
The outer dimensions of the metal body are usefully disposed within a circle drawn around the fastening opening with a radius of 43 mm. The spacing between the center point of the fastening opening and the belt running surface is preferably fixed in a range of from 19 mm to 24 mm.
According to the invention, the metal body forms a system component that is not changed via its construction if the reversing element has to be adapted to the given installation situation. Adaptation to the given installation situation is accomplished by modifying the detachably connected plastic parts, which can be produced at favorable cost in the form of injection-molded components. Modifications can be made by exchanging the plastic profiles, which are laterally connected with the metal body in a detachable manner, so that the reversing element can be used for half-covered installation, covered installation, or also for an external structure. Horizontal installation situations can also be formed. The use of the metal body as a standard component in combination with different plastic components permits a rational manufacture of the reversing elements required for different types of vehicle, and substantially simplifies stockkeeping.
The metal body is preferably produced from a steel sheet material with a thickness of 2 to 4 mm. The shaped areas may have smaller wall thickness values due to the flow processes occurring in the course of cold forming. The metal body can be manufactured by multi-stage cold forming. To produce a turned-over collar on the backside surrounding the eye of the belt, the material has a cut that first forms the upper edging of the belt eye. The material remaining in the area of this belt eye forms a metal sheet tab that is subsequently reshaped to form the backside, forming a turned-over collar. The back side collar formed into the belt eye and the bead-like front side jointly form a wide surface on which the seat belt is running. This running surface has a rounded, curved cross section extending without steps up into the corner areas of the belt eye. The seat belt is safely guided on this wide running surface when the reversing element performs pivotal movements in a crash situation.
In a crash situation, any deformation of the running surface can stabilize the guidance of the seat belt and prevent the seat belt from slipping into a corner of the belt eye. In a preferred embodiment of the invention, the profile of the running surface for the safety belt is designed so that under test conditions, simulating a crash situation, the belt running surface bends so that it centers the seat belt on the running surface. The term xe2x80x9ctest conditionsxe2x80x9d pertains to a front collision test in which the reversing element is installed in a seat belt system. Such a front collision test occurs with a dummy at a preset speed at the time of impact. A support for the seat belt is designed with a relatively elastic bending property, wherein the seat belt is guided in the event of a crash. The thickness of the material and also the width of the reshaped metal sheet segments are factored into the dimensions of the support. The construction is fixed based on strength calculations with the help of a few empirical tests. In a crash, the connected plastic profiles have no bearing on the behavior of the reversing element.
The front side of the belt running surface of the metal body, which is shaped like a bead, has a substantially straight terminating edge. Furthermore, the metal body has a sliding body reducing its resistance to friction. This body may have galvanically applied coatings, such as chrome coatings. These metallic coatings exhibit good resistance to abrasion and have a long useful life. However, superior friction values are obtained if a sliding coating with a fluorine polymer matrix having reinforcing substances is used. This sliding coating should have a thickness of less than 100 xcexcm. While the fluorine polymer matrix of the sliding coating supplies adequate thermal stability, the incorporated, preferably particulate reinforcing substances create a sufficient resistance to abrasion. The low thickness of the coating of less than 100 xcexcm, preferably from 15 xcexcm to 80 xcexcm, assures good dissipation of heat into the metal body. As a result, there is a favorable effect on the heating of the running surface in the event of a crash. Moreover, the coating described above has a distinctly lower emission of noise when the belt is pulled out, as compared to designs jacketed with plastic or chrome-plated coatings.
The plastic adapter, which can be secured on the mounting surface of the metal body, substantially contributes to the proper functioning of the seat belt. This adapter comprises a displacing body that can be fixed on the upper edge of the belt eye which limits the gap width of the belt slot. The gap width is adapted to the seat belt and is selected so that the belt can be moved substantially without coming into contact with the plastic material within the belt slot. This design prevents the formation of folds. The plastic adapter is a guiding element that is not subjected to any stresses in the event of a crash. It can be produced as a simple injection-molded component and secured on the metal body by plug connections. Furthermore, stop elements for limiting the angle of pivot can be molded onto the plastic adapter, forming one single piece with the adapter.
In a preferred embodiment of the invention, the set of structural elements additionally comprise at least one stop disk with stop elements for limiting the pivot angle, which are molded onto this stop disk. This stop disk can be connected to the backside of the plastic adapter and may comprise an opening corresponding with the fastening opening of the metal body. By exchanging the stop disks, it is possible to make adaptations to the permissible pivot angle range in a very simple manner.
An important component of the set of structural components is the set of profiled elements comprising differently shaped plastic profiles, which can be laterally pushed onto the edge profile of the metal body and coupled in pair by a plug connection. If the reversing element is intended for covered or half-covered installation in the post of the body of the vehicle, the plastic profiles act as sight shutters. The plastic profiles have tabs protruding sideways and engage the opening in a covering (or facing) on the side of the vehicle body from behind. This opening receives the edge of the reversing element and permits pivotal movements. Furthermore, the plastic profiles may comprise a circular segment-shaped sight area adjoining the belt running surface of the metal body in a flush manner and wherein it is adapted to the edge of the opening in the facing on the side of the body of the vehicle. The lateral tabs adjoin this sight area with a step. Moreover, by exchanging the plastic profiles, the reversing element can be refitted so that it is also suitable for external mounting on a visible surface in the interior of the vehicle. In such a case, the plastic profiles designed as sight shutters are replaced by rounded edge protection profiles.
Finally, the set of structural components can be expanded by additional cover caps, which can be secured on the front side of the metal body and cover the mounting surface as well as a fastening screw which secures the reversing element on the body of the vehicle. The cover cap is used if the reversing element has to be visibly mounted in the interior of the vehicle.